Four types of I_ATPs and their relationship with NG neuron diameter.

<p>(A) The currents activated by ATP (10⁻⁴ M) in NG were characterized according to fast (F), intermediate (I), slow (S), and very slow (VS) kinetics with an expanded time axis. The horizontal bar above the traces indicates the application of ATP. (B) The 10–90% rising time (ordinate) of different types of ATP (10⁻⁴ M)-activated currents (black circles = type F, red triangles = type I, green squares = for type S, and yellow diamonds = type VS I_ATPs) against neuron diameter. Each point in the graph represents a single cell. The correlation coefficient was 0.66 (<i>p</i><0.05). (C) Representative traces of type F, I, S, and VS ATP (10⁻⁴ M)-activated currents. (D) Comparisons of the absolute ratios of the four types of I_ATPs in different subpopulations (small, medium, and large sizes) of NG neurons. Specifically, F type: small (13/54, 28.9%), medium (36/54, 80.0%), and large (5/45, 11.1%); I type: small (5/75, 6.7%), medium (56/75, 74.7%), and large (14/75, 18.6%); S type: small (11/126, 8.7%), medium (94/126, 74.6%), and large (21/126, 16.7%); VS type: small (7/59, 11.9%), medium (34/59, 57.6%), and large (18/59, 30.5%).